I'll make a wild guess here. If no one answered your request to cannibalize their Panasonic MSX2+ until now, it is not likely it'll happen anytime soon 
dhau just tries to alert people and motivate them to help 
dhau is a lovely guy... But I'll not cease to look after my parts! 
Check eBay. From time to time a defective/non working machine appears, with low price and ready to be disassembled and use it as a spare parts provider
A FX/WX/WSX defective/broken/etc on ebay? Never seen that 
And if I made my WSX work, I'm sure I can make this defective machine works
ok, how can i upgrade my FSA1-WX with 512k ram?
thanx
i need some help right now 
WHERE is the link on the website? and about the 512k RAM..
got the IC's right here so i can start with it..